> Claude Opus 4.1 is a closed AI model from Anthropic, released 5 Aug 2025. Index score 140 (GPT-4 = 100), rank 87 of 229 ranked models. API price $15 in / $75 out per million tokens, 200K context.

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# Claude Opus 4.1

Anthropic

Released 5 Aug 2025

Closed

Flagship

Date verified

[Compare](https://themodelindex.org/compare/claude-opus-4-1-vs-qwen3-235b-a22b-thinking-jul-2025/) [Announcement](https://www.anthropic.com/news/claude-opus-4-1)

140129–152

Index score

#87 of 229 models

6/ 8

Core tests taken

4 of 6 areas · plus 14 anchor tests

−6

Versus the frontier at release

best then: o3

Replaced by [Claude Opus 4.5](https://themodelindex.org/models/claude-opus-4-5/)

$15/ $75

Price per million tokens

input / output, list price

200K

Context window

tokens it reads at once

## Where it sits · on the frontier

_Chart: Model Index score of every scored model since late 2022, with the best closed and best open model over time_

Gemini 2.5 Pro reached this score 4 months earlier.

## Test results · by area · tick = best by any model

Show 9 anchor tests

Reasoning & knowledge

evidence

GPQA Diamond

77%

Humanity's Last Exam

12%

Maths

evidence

FrontierMath T1-3

13%

Coding

evidence

SWE-bench Verified

73%

Terminal-Bench

38%

Agents

evidence

APEX-Agents

no result

Novel problems

no evidence yet

ARC-AGI-2

no result

Long tasks

evidence

METR time horizon

1.9 h

Independent results from the Epoch AI benchmarking hub, best reasoning setting. The core tests are shown here; anchor tests also inform the score and can be shown above.

## What others say · rank on each leaderboard

The Model Index

independent tests, our method

#87

of 219 · 140

Epoch Capabilities Index

overall capability from many benchmarks

#84

of 239 · 144.1

Further left is better. Leaderboards measure different things: LMArena is people voting blind between two answers, the others are test scores. Click any row for the source.

## Best at · top three among current models

3rd

SWE-bench Verified

Epoch AI · independent

Where this model places in the top three of today's models, on category leaderboards and on our core tests.

## Where to use it · prices checked 1 Oct 2026

#### From the lab

Claude

app · subscription

↗

Claude API

API

↗

#### API providers · 1 · per million tokens, in / out

A

Amazon Bedrock

$15 / $75

cheapest

Provider prices come from OpenRouter's live listing; going direct to a provider can differ. Subscriptions are the lab's own apps.

## Facts and sources

Released

5 Aug 2025

Announcement

[anthropic.com ↗](https://www.anthropic.com/news/claude-opus-4-1)

Release entry

Claude Opus 4.1

Scored as

Claude Opus 4.1

Artificial Analysis index

–

Output speed

–

Hugging Face

closed weights

## Anthropic releases · around this one

Claude Opus 4

Closed

22 MAY 2025

index 137

Claude Sonnet 4

Closed

22 MAY 2025

index 135

Claude Opus 4.1

Closed

5 AUG 2025

index 140

Claude Sonnet 4.5

Closed

29 SEP 2025

index 146

Claude Haiku 4.5

Closed

15 OCT 2025

index 137

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Source: https://themodelindex.org/models/claude-opus-4-1/ · The Model Index · data as of 2026-10-01